According to JP-A-2001-295720 and U.S. Pat. No. 6,631,706B1, US2004/0055580A1 (WO00/47888), high pressure fuel pumps are disclosed. In general, a high pressure fuel pump pressurizes fuel drawn into a compression chamber, and discharges the fuel by an axial movement of a plunger. For example, the fuel discharged from the high pressure fuel pump is distributed to an injector provided to each cylinder of an engine via a delivery pipe. The high pressure fuel pump includes a metering valve for controlling an amount of the fuel discharged flowing from the compression chamber, in general. The metering valve is arranged in an inlet of the compression chamber.
In the structure of the high pressure fuel pump disclosed in JP-A-2001-295720, a valve body and an electromagnetic driving portion (solenoid actuator) are integrally constructed in the metering valve. The solenoid actuator operates the valve body, which faces the compression chamber. Therefore, when pressure of fuel in the compression chamber increases, pressure of the fuel is applied to the solenoid actuator integrated with the valve body. In this structure, the rigidity of the solenoid actuator needs to be enhanced such that the solenoid actuator is capable of resisting pressure of the fuel repeatedly applied.
Furthermore, in the structure of the high pressure fuel pump disclosed in U.S. Pat. No. 6,631,706B1 and US2004/0055580A1, the valve body and the solenoid actuator are separately constructed in the electromagnetic valve (solenoid valve). The valve body separated from the solenoid actuator is interposed between the solenoid actuator and a housing defining the compression chamber. However, hydraulic pressure in the compression chamber is applied to a guide member, which guides the movement of the valve body, provided to the solenoid actuator. Therefore, the hydraulic pressure in the compression chamber is applied to the solenoid actuator via the guide member. As a result, the solenoid actuator needs to be firmly fixed to the housing, and the rigidity of the solenoid actuator needs to be enhanced to prevent deformation when the solenoid actuator is fixed to the housing.
In the above structures, the rigidities of both the solenoid valve and the solenoid actuator constructing the solenoid valve need to be enhanced. Therefore, the solenoid valve may become structurally complicated. In addition, the solenoid valve may become jumboized.